Vincent Tabak was jailed for a minimum of 20 years for murdering his next-door neighbour, the landscape architect Joanna Yeates. Photograph: Rex Features

Images of children being abused have been discovered on a computer used by Vincent Tabak, it has emerged.

Police have passed on details to the Crown Prosecution Service, asking if officers should question Tabak in prison over the material.

When police delved into Tabak's computers following his arrest for the murder of Joanna Yeates they found pornography depicting women being strangled, bound and gagged.

Towards the end of his trial it also emerged that police were considering questioning Tabak in relation to other material on his computers.

Sources close to the Tabak investigation confirmed to the Guardian on Tuesday that this material included images of children being sexually abused.

It is understood the material is classed as category four. There are five categories with category one considered the least serious by the courts and five the most.

The police refused to comment on the nature of the material.

Detective Chief Inspector Phil Jones, who led the murder investigation, said only that "during the examination of Vincent Tabak's computer, other material was found. We have referred this matter to the CPS for initial guidance." Once referred to the CPS they will consider a number of criteria before charging someone with an offence. This includes whether it is in the public interest to do so.

The existence of the material – though not what it consisted of – emerged during legal argument. Banning orders were in place for the duration of the trial preventing the media reporting Tabak's interest in pornography featuring adults because the jury had not been allowed to hear about it for fear it would prejudice them against the defendant.

The prosecution argued that the orders ought to stay in place because of a further matter that the police might wish to speak to Tabak about. It said officers would want to question Tabak in prison before the CPS decided if it should prosecute.

However, because these proceedings were at an early stage, the trial judge, Mr Justice Field, ruled that the banning orders ought to fall away at the end of the trial.

Tabak has not been arrested or questioned over the images of abuse.

The jury at Bristol crown court found Tabak guilty of murdering his next-door neighbour, landscape architect Joanna Yeates, 25. Police believe the murder was sexually motivated. Tabak, a 33-year-old Dutch engineer, was jailed for a minimum of 20 years.